This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The nuclear gene xanthine dehydrogenase (Xdh) was sequenced for 247 genera representing all major lineages of angiosperms and gymnosperms and the results need to analyzed using Paup program under likelihood methods. Approximately 1265 bps were sequenced, resulting in 1557 aligned characters, due to the insertion of gaps. Eleven indels ranging from 3-66 bps in length were inserted in the alignment. Of the aligned characters, 1187 (76%) were variable and 1068 (69%) were potentially parsimony-informative. The ti/tv ratio in Xdh was 1.10, indicating that a high level of saturation was not reached. For likelihood analyses the program MODELTEST v. 3.6 (Posada and Crandall, 1998) was used to select the models of nucleotide evolution and is inserted at the end of the dataset. Dataset has been run on a PC however it is very slow and needs a larger computer for analysis.